Railway-traffic-controlling apparatus



July 15, '1930. G. w. BAUGHMAN RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Sept. 24, 1929 INVENTOR. G h/Baui i 7 4m U Patented July 15, 1930 time ATENT .o ricE GEORGE W. BAQGHMALT, or Pmswm PENNSYLVANIA, Assrenoa *ro, THE 'UNIQN' swrrorr & SIGNAL COMPANY, or swrssveLE, PENNSYLVANIA, A CORPORATION or YIPENVNYSYLVANIA RAILWAY-TRAFEIQCONTROLLING ArrAnArUs Application filed September 24, 1929. Serial 1W0 3)4,792. I

My invention rela'tes'to' railway traflic con trolling apparatus, and particularly to continuous inductive train control systems of the code type. In systems. of this character, the code transmitter is usually normally de-energized, and is set into operation when the trackrelay is de-energized due to a train entering the section; It follows that the codetransmitter should be set into operation as promptly as possible'when'atrain enters the section,

and it is usually the release time. of the track relay which determines the interval of time between the entrance ,of the train and'cthe starting of the code transmitter. Direct cur rent track relays, and track'relays of the alternating current centrifugal type, both require an appreciable interval of timefor release after the relay becomes de-energized due-to the entrance of the train into the section, and one feature of my invention is the provision of means for setting the code transmitter into operation before. the track relay actually releases, thereby eliminating the possibility of a flip of the cab signal.

I will describe twoforms of apparatus embodying my invention, and will then point out the novel features thereof in claims.

In the accompanyingdrawing, Fig. 1 is a diagrammatic View showing one form of apparatus embodying my invention applicable for use "with: direct current track circuits- Fig. 2 is a -view similar to Fig. '1, but showing ajmodification of my invention applicable to alternating current track 'circuits.,.

Similar reference characters refer to similar parts in each of the views.

Referring first to Fig. 1, the reference characters 1 and l designate the track rails of a stretch of railway track along which traflic normally moves in the direction indi;

cated by thearrow. These rails are divided byinsulated joints 2 to form tracksections, ofwhich only one complete section'E' F is shown in the drawing.

Section E;-.F.is provided with a'track circuit-comprising a track battery 3 connected across the rails at the feXitflend of-the block (through; the secondary of 'atransformer A hereinatterdestrihed) ,and, a track r lay Bf? connected acrossthe rails at the entrance end of the section.{' c g y r Alternating train governing current is supplied to the rails of section from a transformer 5, the primary of which is con-f nected with a source of alternating current which is notshown in the drawing. The sec-' in advance is energized. The circuit for the i motor M and the circuit for the primary of transformer A'are controlled by front contac'ts 7 and 8 of a'normally de-energized code 'relayD. The code relayD is provided with a circuit which passes from terminal B of a suitable sourceof current, through back contact '6 of track relay R and the winding of the relay D to terminal C of the same source of current. It follows that relay D is normally de-energized, but will be energized when track relay R is open due to the presence of a train n section E-F. When relay D becomes energized, an operatingclrcuit for the motorM will become closed, which cir-- ondary of transformerb is at times connected cuit includes the secondary of transformer 5 and front contact 7 of relay D. At the same time, a circuit for the primary of'transforrner A will become closed, which circuit ineludes the secondary of transformer 5, front contactf8 of relay D, contact 14: of the code transmitter T, and front contact 9 of track relay. R It follows that if track relay I R is energized, alternating train governing current will" be periodically supplied to the rails of sect-ion EF through transformer The circuit for the code relay D is provided-with a branch around back contact' 6 of trackzrelay R which branch includes a polar contactlO of a'polarized relay X. The

winding of thisrelay is connectedwith the Y secondary of a transformer 4, theprimary' V of which is interposed in the connection. betwee he track relay R trade rail -15 Relay X is characterized by the fact that after the relay becomes de-energized, its polarized armature remains in the position to which it was last moved. This relay is so connected in the track circuit that a decrease of the currentin the primary of transformer 4-, in-

duces a current in the secondary which causes.

the polar contact 10 to be shifted to the right, whereas an increase of the current in the primary of transformer l causes this polar contact to be shifted to the left. The operation of the apparatus shown in Fig. 1 is as follows: Normally the circuit for the code relay D is open at both contacts 6 and 10 of relays R and X. When a train enters section Ill-F it will shunt track relay R thereby decreasing the amount of current supplied to the transformer 4, so that the polar contact 10 of relay X ill immediately swing to the right to close the circuit for code'relay D. This operation of contact 10 will occur before the back contact 6 of relay R becomesclosed, so'that the time between the entrance of the train into the section and the energization of code relay D is reduced to a minimum. lVhen the train leaves section EF, the amount of current supplied to relay R and the primary of transformer l will increaseso that relays R and X will be operated to open both contacts 6 and 10, the operation of the code transmitter will then cease.

Referring now to Fig. 2, the apparatus is similar to that shown in Fig. 1, except that the tracl: battery is omitted, .nd alternating track circuit current is normally supplied to transformer A from the secondary of trans former 5 through a back point of contact 8 of the code relay D. lVhen code relay D becomes energized, however, the continuous supply of alternating current to transformer A'will be cut off and altcrna-tim current will be periodically supplied to this transformer through a front point of contact 8, contact I l of code transmitter 'I, and the front contact 9 of track relay R it being assumedthat this latter relay is energized. The track relay, which is designated R is of the alternating current type, and may, foreitample, he a centrifugal relay. The secondary of transformer l is connected with the input terminals of a full-wave rectifier 11, the out put terminals of which are connected with the primary of a transformer The secondary ofthe latter transformer is connected with the winding of the auxiliary polarized relay X. A condenser 13 may be connected'aoross the primary of transformer 12 to smooth out the pulsations in the current supplied by the rectifier l1. Relay X is so connected with the transformer 4 that when the current in this transformer decreases, polar contact 10 will be swung to the right, whereas 'whenthe current in transformer 4 increases polar contact 10 will be swung to the left.

The operation of the apparatus shown in Fig. 2 will be apparent from the foregoing without detailed explanation.

Although I have herein shown and describedonly two forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a section ofrailway track, a track circuit including a track relay for said section, means including a normally de-energized device for supplying train controlling current to the rails of said section, a circuit for said device including a back contact of said track relay, a shunt for said circuit around said contact, and means receiving current from the connection between said relay and one track rail for closing said shunt before said relay contact closes when a train enters said section.

2. In combination, a section of railway track, a track circuit including a track relay for said section, means including a normally de energized device for supplying train controlling current to the rails of said section, a circuit for said device including a back contact of said tracl: relay, a shunt for said circuit around said contact, a transformer the primary of which is interposed between said track relay and one track rail, and means receiving current from the secondary of said transformer for closing said shuntbefore said relay contact closes when a train enters section.

3. In combination, a section of railway track, a track circuit including a track relay for said section, means including a normally de-energized device for supplying train controlling current to the rails of said section, a circuit for said device including a back contact of said track relay, a shunt for said circuit around said contact, a transformer the primary of whichisinterposed between said track relay and one track rail, and a polarized relay receivin current from the secondary of said transformer for closing said shunt before said track relay contact closes when a train enters said section.

4:. In combination, a section of railway track, a track circuit including a track relay forsaid section, means including a normally de-energized device for supplying train controlling current to the rails of said section, a circuit for, said device including a back contact of said track relay, a shunt for said circuit around saidcontact, a polarized relay characterized by the fact that when it becomes de-energized its polar armature remains in the position'to which it was last operated,

a polar contact of said relay being included in said shunt, and a transformer the primary of which is interposed between saidtraclr relay and one track rail, and the secondary of which isconnected with said polarized relay in such direction that increase of thecurrent in the primary causes said polar contact to open and a decrease of the current in the primary causes said polar contact to close.

5. In combination, a section of railway track, a track circuit including a track relay for said section, means including a normally de-energized device for supplying train controlling current to the rails of said section, means for energizing said device when said track relay is open, and means receiving current from the connection between said track relay and one of the track rails for setting said device into operation before the track relay opens when a train enters said section. V 6. In comblnatlon, a sectlon of railway track, a track circuit including a track relay for said section, means including a normally de-energized device'forsupplying train controlling current to the rails of said section, a polarized relay receiving current from the connection between said track relay and one of the track rails, and means for controlling said device jointly by said track relay and ,7

said polarized relay.

7. In combination, 'a section ofrailway track, an alternating current track circuit including a track relay for saidjsection, a transformer having its primary interposed between said track relayand one'of the track rails, a rectifier connected with the secondary of said transformer, a second transformer the primary of which is connected with the output terminals of said rectifier, a polarized relay connected with the secondary of said second transformer, and means controlled jointly by said track relay and said polarized relay for supplying train governing current to the rails of said section.

8. In combination, a section of railway track, a' track circuit including a track relay for said section, an auxiliary relay receiving current from the connection between said track relay and one of the track. rails and characterized by the fact that it responds more quickly than the track relay to the entrance of a train into thesection, and means controlled jointly by said track relay and said auxiliary relay for supplying train governing current to the rails of said section.

In testimony whereof I affix my signature.

GEORGE W. BAIJ'GHMAN. 

